Great summary, can aggree on quite everything.
The Story in Avernum 1 was probably a little bit better in dragging you in, but it had a very bad ending part which lost any logic. Like the companion quests which felt like tucked on afterwards. Much better implemented in the second game as you wrote. I particularily like that you actually have choices in the Spiderweb games. While in Bioware games you have the coice between good and evil, and essentially in 90% as a "good" character you can't really chose (because the other option would just be absurd), in Spiderweb games both sides makes sense in some way without putting you into the "good" or "evil" corner.

For me the combat imbalance played a bigger factor, but I also play games for challenge partially. And if you don't play the game on Torment that's probably not much of a factor.